* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Arial, sans-serif;
}

body {
    background-color: #f5f7fa;
    color: #333;
    line-height: 1.6;
    font-family: Arial, sans-serif;
}

/* 导航栏样式 */
.navbar {
    background-color: #1a5fb4;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.logo {
    color: white;
    font-size: 28px;
    font-weight: 700;
    letter-spacing: 1px;
}

.nav-links {
    display: flex;
    list-style: none;
}

.nav-links li {
    margin-left: 10px;
}

.nav-links a {
    color: white;
    text-decoration: none;
    padding: 10px 20px;
    border-radius: 4px;
    font-weight: 600;
    font-size: 24px;
    transition: background-color 0.3s;
}

.nav-links a:hover {
    background-color: rgba(255, 255, 255, 0.15);
}

.nav-links a.active {
    background-color: rgba(255, 255, 255, 0.2);
}

/* 轮播图样式 */
.carousel-container {
    width: 100%;
    height: 400px;
    overflow: hidden;
    position: relative;
}

.carousel-slide {
    display: none;
    width: 100%;
    height: 100%;
    position: absolute;
    top: 0;
    left: 0;
}

.carousel-slide.active {
    display: block;
}

.carousel-slide img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.slide-content {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    padding: 30px;
    background: linear-gradient(transparent, rgba(0, 0, 0, 0.7));
    color: white;

    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
}

.slide-content h2 {
    color: white;
    font-size: 36px;/*会议主题信息，最顶端*/
    margin-bottom: 8px;
}

.slide-content p {
    font-size: 20px;/*会议日期时间地点*/
    max-width: 800px;
}

.carousel-dots {
    position: absolute;
    bottom: 15px;
    right: 20px;
    display: flex;
}

.carousel-dots.hidden {
    display: none;
}

.dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background-color: rgba(255, 255, 255, 0.5);
    margin: 0 5px;
    cursor: pointer;
    transition: background-color 0.3s;
}

.dot.active {
    background-color: white;
}

.carousel-nav {
    position: absolute;
    top: 50%;
    width: 100%;
    display: flex;
    justify-content: space-between;
    padding: 0 15px;
    transform: translateY(-50%);
}

.carousel-nav.hidden {
    display: none;
}

.carousel-nav button {
    background-color: rgba(0, 0, 0, 0.5);
    color: white;
    border: none;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    font-size: 20px;/**/
    cursor: pointer;
    transition: background-color 0.3s;
}

.carousel-nav button:hover {
    background-color: rgba(0, 0, 0, 0.8);
}

/* 倒计时器样式 - 根据图片调整 */
.countdown-container {
    background-color: #1a5fb4; /* 蓝色背景 */
    padding: 25px 20px;
    margin: 30px auto;
    max-width: 1000px;
    border-radius: 8px;
    box-shadow: 0 6px 20px rgba(255, 107, 53, 0.2);
}

.countdown-title {
    text-align: center;
    color: white;
    font-size: 22px;/*倒计时最上方内容*/
    margin-bottom: 20px;
    font-weight: 700;
}

.countdown {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
}

.countdown-item {
    text-align: center;
    margin: 0 15px;
    min-width: 120px;
}

.countdown-value {
    font-size: 48px;/*时间数字，倒数*/
    font-weight: 800;
    color: white;
    line-height: 1;
    margin-bottom: 5px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
}

.countdown-label {
    font-size: 16px;
    color: rgba(255, 255, 255, 0.9);/*时分秒的英文*/
    font-weight: 500;
    letter-spacing: 1px;
}

.countdown-subtitle {
    text-align: center;
    color: white;
    font-size: 22px;/*to HWCVD2026....*/
    margin-top: 20px;
    font-weight: 600;
}

/* 主要内容区域 - 左右布局 */
.main-container {
    max-width: 1080px; /* 增加最大宽度 ，针对侧边栏*/
    margin: 0 auto;
    padding: 15px 25px; /* 增加左右内边距 */
    display: flex;
    gap: 20px; /* 减少间距，使左右更紧凑 */
}

/* 左侧导航栏 - 根据图片设计改为蓝绿色 */
.left-nav {
    width: 240px;
    flex-shrink: 0;
}

.side-nav {
    background-color: #5F9EA0; /* 蓝绿色背景 - 根据图片调整 */
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
    padding: 0; /* 移除顶部和底部内边距 */
    position: sticky;
    top: 90px; /* 70px导航栏高度 + 20px间距 */
    overflow: hidden; /* 确保圆角效果 */
    margin-left: 20px; /* 向左移动 */
}

.nav-item {
    padding: 15px 20px;
    border-left: 4px solid transparent;
    transition: all 0.3s;
    border-bottom: 1px solid rgba(255, 255, 255, 0.3); /* 添加分隔线 */
    cursor: pointer;
}

.nav-item:last-child {
    border-bottom: none; /* 最后一个没有分隔线 */
}

.nav-item:hover {
    background-color: #4c7d80; /* 悬停时稍深的蓝绿色 */
    border-left-color: #3a5f61; /* 蓝绿色边框 */
}

.nav-item.active {
    background-color: #3a5f61; /* 激活状态 - 深蓝绿色背景 */
    border-left-color: #2a4546; /* 更深的蓝绿色边框 */
}

.nav-item.active a {
    color: white; /* 激活状态白色文字 */
    font-weight: 700;
}

.nav-item a {
    color: white; /* 白色文字，与图片一致 */
    text-decoration: none;
    font-weight: 600;
    font-size: 16px;/*侧边功能筛选栏*/
    display: block;
    transition: color 0.3s;
}

/* 右侧内容区域 */
.right-content {
    flex: 1;
    display: flex;
    justify-content: center; /* 使内容区域居中 */
}

/* 首页内容区域 */
.home-content {
    width: 120%;
    max-width: 1080px; /* 限制内容区域最大宽度 */
}

/* 注册页面内容区域 */
.registration-content {
    width: 120%;
    max-width: 1080px; /* 限制内容区域最大宽度 */
}

.page-content {
    display: none;
    animation: fadeIn 0.5s ease;
}

.page-content.active {
    display: block;
}

.page-title {
    color: #1a5fb4;
    font-size: 32px;/*Welcome to HWCVD 12,  registration标题*/
    margin-bottom: 25px;
    padding-bottom: 10px;
    border-bottom: 2px solid #eaeaea;
}

/* 添加特殊区域 - 在content-box上方但不属于content-box */
.special-section {
    background-color: white;
    border-radius: 8px;
    padding: 20px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
    transition: transform 0.3s, box-shadow 0.3s;
    width: 110%; /* 使内容框稍微窄一些，看起来更居中 */
    max-width: 1080px; /* 限制最大宽度 */
    margin-bottom: 25px; /* 与content-box间距 */
    margin-left: auto;
    margin-right: auto;
}

.special-section:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 15px rgba(0, 0, 0, 0.08);
}

/* 特殊区域标题样式 - 单个h2修改字体颜色 */
.special-section h2 {
    color: #1a5fb4; /* 使用蓝色 */
    margin-bottom: 15px;
    font-size: 22px;
    display: flex;
    align-items: center;
    border-left: 4px solid #1a5fb4; /* 左侧橙色边框 */
    padding-left: 20px; /* 左侧内边距 */
}

.special-section h2 i {
    margin-right: 10px;
    font-size: 22px;
    color: #1a5fb4; /* 图标颜色与标题一致 */
}

.special-section p {
    margin-bottom: 12px;
    font-size: 18px;
    line-height: 2.0;
}

/* 修改为每个内容框占一行 */
.content-container {
    display: flex;
    flex-direction: column;
    gap: 25px;
    align-items: center; /* 使内容框居中 */
}

.content-box {
    background-color: white;
    border-radius: 8px;
    padding: 40px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
    transition: transform 0.3s, box-shadow 0.3s;
    width: 95%; /* 使内容框稍微窄一些，看起来更居中 */
    max-width: 1080px; /* 内容即是正文框，限制最大宽度 */
    scroll-margin-top: 100px; /* 为锚点跳转添加滚动边距 */
}

.content-box:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.08);
}

.content-box h2 {
    color: #1a5fb4; /* 默认的蓝色 */
    margin-bottom: 15px;
    font-size: 32px;/*正文标题*/
    display: flex;
    align-items: center;
}

.content-box h2 i {
    margin-right: 10px;
    font-size: 20px;/*图标大小*/
}

.content-box p {
    margin-bottom: 12px;
    font-size: 20px;/*全文正文*/
    line-height: 2.0;
}

.content-box ul, .content-box ol {
    padding-left: 15px;
    margin-bottom: 15px;
}

.content-box li {
    margin-bottom: 8px;
}

.event-info {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 20px;
    margin-top: 30px;
}

.info-card {
    background-color: #f0f7ff;
    padding: 40px;
    border-radius: 8px;
    border-left: 4px solid #1a5fb4;
}

.info-card h3 {
    color: #1a5fb4;
    margin-bottom: 10px;
}

/* 通知区域 - 根据图片设计 */
.notice-section {
    background-color: white;
    border-radius: 8px;
    padding: 20px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
    margin-top: 30px;
    width: 95%; /* 与内容框保持一致 */
    max-width: 1080px; /* 限制最大宽度 */
    margin-left: auto;
    margin-right: auto;
}

.notice-title {
    color: #1a5fb4;
    font-size: 32px;/*Notice标题*/
    margin-bottom: 20px;
    padding-bottom: 40px;
    border-bottom: 2px solid #eaeaea;
}

.notice-item {
    padding: 40px;
    border-bottom: 1px solid #eee;
    cursor: pointer;
    transition: background-color 0.3s, transform 0.2s;
}

.notice-item:hover {
    background-color: #f8f9fa;
    transform: translateX(5px);
}

.notice-item:last-child {
    border-bottom: none;
}

.notice-item h3 {
    color: #333;
    font-size: 20px;/*Notice正文*/
    margin-bottom: 5px;
    transition: color 0.3s;
}

.notice-item:hover h3 {
    color: #1a5fb4;
}

.notice-date {
    color: #000000;
    font-weight: 600;
    font-size: 18px;/*Notice日期*/
}

/* 模态框样式 */
.modal-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.7);
    z-index: 2000;
    justify-content: center;
    align-items: center;
}

.modal-content {
    background-color: white;
    border-radius: 8px;
    width: 90%;
    max-width: 600px;
    max-height: 80vh;
    overflow-y: auto;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
    animation: modalFadeIn 0.3s ease;
}

.modal-header {
    background-color: #1a5fb4;
    color: white;
    padding: 20px 25px;
    border-radius: 8px 8px 0 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-header h2 {
    color: white;
    font-size: 16px;
    margin: 0;
}

.close-btn {
    background: none;
    border: none;
    color: white;
    font-size: 16px;
    cursor: pointer;
    line-height: 1;
    padding: 0;
    width: 30px;
    height: 30px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform 0.2s;
}

.close-btn:hover {
    transform: scale(1.2);
}

.modal-body {
    padding: 25px;
}

.modal-date {
    color: #000000;
    font-weight: 600;
    font-size: 16px;
    margin-bottom: 15px;
}

.modal-body p {
    margin-bottom: 15px;
    font-size: 16px;
    line-height: 1.7;
}

.modal-footer {
    padding: 20px 25px;
    border-top: 1px solid #eee;
    text-align: right;
}

.modal-btn {
    background-color: #1a5fb4;
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 4px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.3s;
}

.modal-btn:hover {
    background-color: #0f4a8f;
}

/* 表单样式 */
.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: #444;
}

.form-group input, 
.form-group select, 
.form-group textarea {
    width: 100%;
    padding: 12px 15px;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 16px;/*表格文本框*/
}

.form-group input:focus, 
.form-group select:focus, 
.form-group textarea:focus {
    outline: none;
    border-color: #1a5fb4;
    box-shadow: 0 0 0 2px rgba(26, 95, 180, 0.2);
}

.btn {
    background-color: #1a5fb4;
    color: white;
    border: none;
    padding: 12px 30px;
    border-radius: 4px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.3s;
}

.btn:hover {
    background-color: #0f4a8f;
}

/* 页脚 */
.footer {
    background-color: #1a1a1a;
    color: #ccc;
    text-align: center;
    padding: 25px 20px;
    margin-top: 40px;
}

/* 动画效果 */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes modalFadeIn {
    from { opacity: 0; transform: translateY(-20px) scale(0.9); }
    to { opacity: 1; transform: translateY(0) scale(1); }
}

/* 响应式设计 */
@media (max-width: 1200px) {
    .main-container {
        max-width: 1200px;
        padding: 30px 30px;
        gap: 20px;
    }
    
    .content-box, .notice-section, .special-section {
        width: 98%;
    }
}

@media (max-width: 992px) {
    .main-container {
        flex-direction: column;
        padding: 30px 20px;
        gap: 20px;
    }
    
    .left-nav {
        width: 100%;
    }
    
    .side-nav {
        position: static;
        display: flex;
        flex-wrap: wrap;
        justify-content: center;
        padding: 0;
        margin-left: 0;
        margin-bottom: 30px;
    }
    
    .nav-item {
        border-left: none;
        border-bottom: 1px solid rgba(255, 255, 255, 0.3);
        padding: 12px 15px;
        flex: 1;
        min-width: 150px;
        text-align: center;
    }
    
    .nav-item:hover, .nav-item.active {
        border-left: none;
        border-bottom-color: #3a5f61;
    }
    
    .right-content {
        justify-content: center;
    }
    
    .home-content, .registration-content {
        max-width: 100%;
    }
    
    .content-box, .notice-section, .special-section {
        width: 100%;
        max-width: 100%;
    }
    
    .modal-content {
        width: 95%;
        max-width: 95%;
    }
}

@media (max-width: 768px) {
    .navbar {
        flex-direction: column;
        height: auto;
        padding: 15px 20px;
    }
    
    .logo {
        margin-bottom: 15px;
    }
    
    .nav-links {
        width: 100%;
        justify-content: center;
    }
    
    .nav-links li {
        margin: 0 5px;
    }
    
    .nav-links a {
        padding: 8px 15px;
        font-size: 15px;
    }
    
    .carousel-container {
        height: 300px;
    }
    
    .slide-content h2 {
        font-size: 24px;
    }
    
    .slide-content p {
        font-size: 14px;
    }
    
    .countdown-value {
        font-size: 36px;
    }
    
    .countdown-label {
        font-size: 14px;
    }
    
    .countdown-item {
        margin: 0 8px;
        min-width: 80px;
    }
    
    .countdown-title {
        font-size: 20px;
    }
    
    .countdown-subtitle {
        font-size: 16px;
    }
    
    .page-title {
        font-size: 28px;
    }
    
    .modal-header h2 {
        font-size: 20px;
    }
    
    .modal-body {
        padding: 20px;
    }
}

@media (max-width: 480px) {
    .carousel-container {
        height: 250px;
    }
    
    .slide-content {
        padding: 20px;
    }
    
    .slide-content h2 {
        font-size: 20px;
    }
    
    .countdown-value {
        font-size: 28px;
    }
    
    .countdown-item {
        margin: 0 5px;
        min-width: 60px;
    }
    
    .countdown-container {
        padding: 20px 15px;
    }
    
    .side-nav {
        flex-direction: column;
    }
    
    .nav-item {
        width: 100%;
        text-align: center;
    }
    
    .modal-header {
        padding: 15px 20px;
    }
    
    .modal-header h2 {
        font-size: 20px;
    }
    
    .modal-body {
        padding: 15px;
    }
}